obsQuantiles: Calculate model fit
In DstarM: Analyze Two Choice Reaction Time Data with the D*M Method

This function is nothing but a wrapper for quantile.

1	obsQuantiles(data, probs = seq(0, 1, 0.01), what = "cr")

`data`	A dataframe with: a column named `rt` containing response times in ms, a column named `response` containing at most 2 response options, and an optional column named `condition` containing a numeric index as to which conditions observations belong.
`probs`	vector of probabilities for which the corresponding values should be called
`what`	Character. `'cr'` if the quantiles are to be calculated per condition-response pair, `'c'` if the quantiles are to be calculated per condition, and `'r'` if the quantiles are to be calculated per response.

tt = seq(0, 5, .01)
pars = c(.8, 2, .5, .5, .5, # condition 1
        .8, 3, .5, .5, .5,  # condition 2
        .8, 4, .5, .5, .5)  # condition 3
pdfND = dbeta(tt, 10, 30)
# simulate data
data = simData(n = 3e3, pars = pars, tt = tt, pdfND = pdfND)
probs = seq(0, 1, .01)
q = obsQuantiles(data, probs = probs)
matplot(probs, q, type = 'l', las = 1, bty = 'n')